Field of the Invention
The invention relates to a FPC connector, more particularly to a multiple-piece FPC connector disposing an insulation seat and a cover separately to constitute a multiple-piece structure.
Descriptions of the Related Art
In various modern electronic equipments, multiple printed circuit boards (referred to as PCB hereinafter) are usually necessary to provide different electrical functions. Most electrical signal deliveries between each of the PCBs are currently achieved by flexible printed circuit board (referred to as FPC hereinafter) and the FPC connector built on the PCB. However, with the development trend of thinner and smaller electronic equipment, internal space of the electronic equipment is reduced significantly such that the dimensions of various FPC connectors are forced to be reduced. In practice, The height dimension of the FPC connector has been reduced from early 2.0 mm to 0.5˜0.6 mm, while the pitch dimension of the electric conduction terminals of the FPC connector has been changed from 1.0 mm to 0.2˜0.3 mm particularly.
In order to meet the requirement of electrical signal delivery, the FPC connectors of partial specifications are even equipped with nearly a hundred of electric conduction terminals. There is considerable technical difficulty to dispose so many electric conduction terminals in the FPC connector with respect to either design or fabrication. Refer to FIG. 1, which is a schematic view showing an action of an FPC connector plug technique widely used in the industry currently. As shown in FIG. 1, electric conduction terminals 3, 4 on both left and right sides are inserted into terminal insertion holes 21, 22 reserved on both left and right sides of a connector body 2 laterally by a plug equipment, and a clamping force is provided to the electric conduction terminals 3, 4, respectively, by forming walls of the terminal insertion holes 21, 22 to accomplish assemblage of the FPC connector. The connector body 2 is usually made by means of insert molding, so that residual stress of molding always exists inside the connector body 2.
Moreover, during insertion of the electric conduction terminals 3, 4, interference and extrusion with the connector body 2 cannot be avoided, such that generation of insertion internal stress inside the connector body 2 cannot be avoided. As such, although flatness of SMT pins of electric conduction terminals meet product design requirement after normal temperature assemblage, the residual stress inside the connector body will be released due to high temperature as the FPC connector undergoes high temperature process for SMT, such that warpage deformation on two sides or other portions of the connector body is induced to destroy the flatness of the SMT pins, so that missing solder phenomenon might occur.
Furthermore, conventional FPC connectors are limited to dimension and terminal quantity usually, such that the thickness of the walls of the above terminal insertion holes for the connector body is constrained considerably. As such, not only the difficulty of making and molding the connector body will increase, but also the connector body might be incapable of providing sufficient clamping force for the electric conduction terminals, so that electric conduction terminals may be detached from the connector body easily, such that the FPC connector loses the original electrical signal delivery function.
According to structural form, current FPC connectors may be divided into three categories roughly, including forward overturning based, rearward overturning based and drawer based FPC connectors, among which, the rearward overturning based FPC connector is the most common one. In the rearward overturning based FPC connector, a rotatable actuation body (known as SLIDER) is disposed on a rear end of the connector body. As the actuation body rotates to an actuation state, the elastic arms of the electric conduction terminals are forced to deform, such that electrical connection with FPC is achieved. Generally, plastic material will be selected for the actuation body in order to avoid electrical short circuit between electric conduction terminals. However, as the actuation body made of plastic material is in rotation, abrasion due to contact with the electric conduction terminals cannot be avoided, and the abrasion for the actuation body will get severer as the number of rotations increases, such that the capability of the actuation body forcing the elastic arms of the electric conduction terminals to deform is reduced significantly, so that the joint pressure of the electric conduction terminals that can be provided to the FPC keeps decreasing. Thus, only 10 to 20 times of normal uses are guaranteed for the rearward overturning based FPC connector in the industry now. In addition, due to poor ductility of plastic material, the actuation body made of plastic material is prone to fracture and detachment destroying under force. Such situation is criticized in industries, but there is no thorough solution in the industries.
From above description, those skilled in the art are seeking for providing a FPC connector to solve various problems for above conventional FPC connectors effectively.